From 9b5d627a5567c25d8c1bf308881ca3a0c46009a8 Mon Sep 17 00:00:00 2001
From: Colin Adler <colin1adler@gmail.com>
Date: Mon, 17 Oct 2022 11:47:45 -0500
Subject: [PATCH] fix(tailnet): data race in `coordinator.Close()` (#4589)

---
 tailnet/coordinator.go | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/tailnet/coordinator.go b/tailnet/coordinator.go
index 4216bbc624..ded78e64aa 100644
--- a/tailnet/coordinator.go
+++ b/tailnet/coordinator.go
@@ -338,10 +338,10 @@ func (c *coordinator) handleNextAgentMessage(id uuid.UUID, decoder *json.Decoder
 func (c *coordinator) Close() error {
 	c.mutex.Lock()
 	if c.closed {
+		c.mutex.Unlock()
 		return nil
 	}
 	c.closed = true
-	c.mutex.Unlock()
 
 	wg := sync.WaitGroup{}
 
@@ -365,6 +365,8 @@ func (c *coordinator) Close() error {
 		}
 	}
 
+	c.mutex.Unlock()
+
 	wg.Wait()
 	return nil
 }